Improvement in mortise-chisels



E. CARNEY. MORTISE CHISEL.

, 192,323. Patented June 26,1877

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EDWIN GARNEY, OF LOGKPORT, NEW YORK.

IMPROVEMENT IN MORTlSE-CHISELS.

Specification forming part of Letters Patent No. 192,323, dated June 26, 1877 application filed April 26, 1877.

To all whom it may concern Be it known that I, EDWIN GARNEY, of Lockport, in the county of Niagara and State of New York, have invented certain new and useful Improvements on a Double-Edged Mortise-Ghisel; and I do hereby declare that the following description of my said invention, taken in connection with the accompanying sheet of drawings, forms a full, clear, and exact specification, which will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved article of manufacture--a double-edged mortisingchisel for hand or machine mortising; and it consists of a suitable body having aV-shaped excision on its end, so as to form two cuttingedges, said body being tapering from the cutting toward the socket or shank end, and swelled from the edges toward the center, whereby a mortise having parallel sides can be readily produced, as hereinafter first fully described and then pointed out in the claim. 1

In the drawings heretofore mentioned, which form a part of this specification, and serve to illustrate my invention more fully Figure l is a perspective view of my improved mortise-chisel. Fig. 2 is an end view of the same. Fig. 3 is a longitudinal section. Fig. 4 is a plan of the cutting-edges; and Fig. 5, a transverse section in line w w of Fig. 1.

Like letters of reference indicate corresponding parts in all the figures,

A is the body of a mortise-chisel provided with either a socket for the insertion of a handle or with means whereby it can be secured to a mortising-machine. This body has on its extremity a V-shaped excision, G, to produce two cutting-edges, B B, on the narrower sides of the said b5dy'. It is furthermore tapering or decreasing in size toward the shank or socket end, so as to enable a ready withdrawal of the chisel from the mortise, and longitudinally swelled or increased in thickness from the edges toward the center line D, to make the longitudinal sides of a mortise parallel and rectilinear, which latter the central swell, on account 'of the body of the chisel being tapering, and therefore smaller in the bottom of the V-shaped excision than on the cutting-edges thereof. This swell is of exactly the same diiference in the transverse section of the body A as that between the points b and (1 thereof, whereby the lines I) d are exactly parallel, and therefore a mortise of the same configuration. I have illustrated this swell in the body A in the various figures, particularly in Fig. 5, which shows this feature somewhat exaggerated.

A chisel, as described, possesses virtually six cutting-edges, viz., the edges B B, and the edges on the lines b d, which latter, being oblique cutting-edges, produce a draw-cut and thereby a mortise of superior finish and accuracy.

It is obvious that, While different sizes of chisels should preferably be used for the various widths of mortises, one chisel will pro duce any length of mortise, in the following manner:

In the place where a mortise is to be put, a hole is first bored or drilled of nearly or the same diameter as the width of the mortise, and the chisel entered therein, the chips passing into or through the said hole. If the mortise is to be made longer, the same is elongated by using either one of the cuttingedges B, care being taken not to take too heavy cuts.

It will be readily observed that this kind of mortise-chisel is applicable to both hand and machine mortising without change or modification.

Having thus fully described my invention, I desire to secure to me by Letters Patent of the United States As animproved article of manufacture, a mortise-chisel having two cutting-edges, B B, produced by the excision G, the body of said chisel being made tapering or decreasing in size toward the socket or shank end, and longitudinally swelled along the lines 61 D, the whole constructed and arranged as hereinbefore set forth and stated.

In testimony that I claim the foregoing as my invention I have hereto set my hand and affixed my seal in the presence of two subscribing witnesses.

EDWIN GARNEY. [L. s.]

Attest Mmmr. J. smmr, FRANK HIBSGE. 

